Data fusion generally involves the concept of combining data items from multiple, distributed, and/or heterogeneous data sources. Data fusion is a powerful tool and can be used, for example, to assist a user with any one or more of a variety of tasks, such as recognition, identification, tracking, change detection, decision making, and prediction, among other things. These tasks are improved by integrating data from multiple sources. In many situations, however, the heterogeneity of the data derived from or held in disparate sources creates substantial hurdles to fusing that data.